• Title, Summary, Keyword: biosensor

Search Result 642, Processing Time 0.045 seconds

Effect of Bioluminescence Stimulating Agent of the Genetically Engineered Strain KG1206 on the Monitoring of the Petroleum Hydrocarbon Contaminated Groundwater Samples (발광유전자 재조합 균주 활성 촉진 조건이 석유계 탄화수소 오염지하수 모니터링에 미치는 영향)

  • Ko, Kyung-Seok;Kong, In-Chul
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.30 no.1
    • /
    • pp.79-84
    • /
    • 2008
  • This paper describes the application of bioluminescence stimulating agents on a genetically engineered microorganism, Pseudomonas putida mt-2 KG1206, to monitor toluene analogs using in groundwater samples from petroleum hydrocarbon contaminated sites. The maximum bioluminescent response with pure chemicals followed in the order: m-methyl benzyl alchohol > m-toluate > toluene > m-xylene > benzoate > p-xylene > o-xylene. Generally, the bioluminescence production of strain mixed with groundwater samples was dependent on the contaminated total inducer concentrations. However, few samples showed opposite results, where these phenomena may be caused by the complexicity of environmental samples. Two chemicals, SL(sodium lactate) and KNO$_3$, were tested to determine a better bioluminescence stimulant. Both chemicals stimulate the bioluminescence activity of strain KG1206, however, a slightly high bioluminescence was observed with nitrogen chemical. This selected stimulant was then tested on samples collected from contaminated groundwater samples. The bioluminescence activity of all samples mixed with the strain was stimulated with KNO$_3$ amendment. This suggests that the low bioluminescence activity exhibited by the environmental groundwater samples can be stimulated by amending the culture with a proper agent, such as nitrogen compound. These findings would be useful, especially, when strain was used to monitor the groundwater samples contaminated with low inducer contaminants. Overall, the results of this study found the ability of bioluminescence producing bacteria to biosensor a specific group of environmental contaminants, and suggest the potential for more efficient preliminary application of this engineered strain in a field-ready bioassay.

Minority report; Diketopiperazines and Pyocyanin as Quorum Sensing Signals in Pseudomonas aeruginosa (Minority report; Pseudomonas aeruginosa의 정족수 인식(쿼럼 센싱) 신호물질로써의 Diketopiperazines과 Pyocyanin)

  • Lee, Joon-Hee
    • Korean Journal of Microbiology
    • /
    • v.44 no.2
    • /
    • pp.85-92
    • /
    • 2008
  • Pseudomonas aeruginosa is an opportunistic human pathogen, causing a wide variety of infections including cystic fibrosis, microbial keratitis, and burn wound infections. The cell-to-cell signaling mechanism known as quorum sensing (QS) plays a key role in these infections and the QS systems of P. aeruginosa have been most intensively studied. While many literatures that introduce the QS systems of P. aeruginosa have mostly focused on two major acyl-homo serine lactone (acyl-HSL) QS signals, N-3-oxododecanoyl homoserine lactone (3OC12) and N-butanoyl homoserine lactone (C4), several new signal molecules have been discovered and suggested for their significant roles in signaling and virulence of P. aeruginosa. One of them is PQS (Pseudomonas quinolone signal; 2-heptyl-3-hydroxy-4-quinolone), which is now considered as a well-characterized major signal meolecule of P. aeruginosa. In addition, recent researches have also suggested some more putative signal molecules of P. aeruginosa, which are diketopiperazines (DKPs) and pyocyanin. DKPs are cyclic dipeptides and structurally diverse depending on what amino acids are involved in composition. Some DKPs from the culture supernatant of P. aeruginosa are suggested as new diffusible signal molecules, based on their ability to activate Vibrio fischeri LuxR biosensors that are previously considered specific for acyl-HSLs. Pyocyanin (1-hydroxy-5-methyl-phenazine), one of phenazine derivatives produced by P. aeruginosa is a characteristic blue-green pigment and redox-active compound. This has been recently suggested as a terminal signaling factor to upregulate some QS-controlled genes during stationary phase under the mediation of a transcription factor, SoxR. Here, details about these newly emerging signaling molecules of P. aeruginosa are discussed.

Comparison of Marine Luminescence Bacteria and Genetically Modified Luminescence E. coli, for Acute Toxicity of Heavy Metals (재조합 발광대장균과 해양 발광 미생물을 이용한 중금속 급성독성평가)

  • Lee, Sang-Min;Bae, Hee-Kyung
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.27 no.8
    • /
    • pp.900-906
    • /
    • 2005
  • The responses of two luminescence-based biosensors were studied on various heavy metals in aqueous solutions. One was recombinant E. coli ($DH5{\alpha}$/pSB311), genetically modified luminescence-based bacteria, and the other was Vibrio fisheri used for the LumisTox system. The recombinant E. coli was marked with the lux CDABE gene from multicopy plasmid, pACYC184, originally isolated from Photorhabdus luminescens. The $DH5{\alpha}$/pSB311 had a characteristic of no organic substrate for its luminescence reaction. Among the tested heavy metals Zinc and cadmium were less toxic than copper and mercury. The recombinant E. coli was more sensitive to toxicity of heavy metals than the LumisTox. The order of toxicity of the heavy metals to the recombinant E. coli was $Hg^{2+}>Cu^{2+}>Zn^{2+}>Cd^{2+}$. In case of the LumisTox, the order of the toxicity of heavy metals was $Hg^{2+}>Cu^{2+}>Cd^{2+}>Zn^{2+}$. The genetically modified luminescence-based biosensor offers a range of sensitive, rapid, and easy to use methods for assessing the potential toxicity of heavy metals in aqueous samples.

Functional Expression of Anti-BNP scFv in E. coli Cytoplasm for the Detection of B-type Natriuretic Peptide (B-type natriuretic peptide 분석을 위한 항 BNP scFv 항체의 대장균 세포질 내에서의 기능적 발현)

  • Maeng, Bo-Hee;Nam, Dong-Hyun;Kim, Yong-Hwan
    • KSBB Journal
    • /
    • v.24 no.6
    • /
    • pp.591-597
    • /
    • 2009
  • B-type natriuretic peptide is a neurohormone secreted in the cardiac ventricles. BNP levels are elevated in patients with ventricular dysfunction. Therefore, the concentration of BNP is important factor to reflect diagnosis and prognosis for cardiovascular disease. In this respect, anti-BNP scFv is an urgent requirement for early diagnosis in the field of biosensor. Herein, the genetic codes of anti-BNP scFv were chemically synthesized and cloned into both pET22b (+) and pColdⅣ vector, respectively. The recombinant scFv was successfully expressed as a functional form in cytoplasm of E. coli and detected through Western blot and ELISA. The highest level of functional expression of anti-BNP scFv was achieved using pET22b (+) vector at $15^{\circ}C$ by addition of 0.1 mM IPTG. Additionally, being exposed to both BNP and ANP, anti-BNP scFv specifically captured only BNP. Therefore, anti-BNP scFv expressed in this study will be applied to measure the concentration of BNP as a diagnostic recognition molecule.

Real-Time Glutamate Release in Rat Striatum of 11-Vessel-Occlusion Ischemia Model Treated with Acupuncture (11개 혈관 차단법을 통한 중증 뇌경색 모델에서 뇌손상 측정과 침치료 효과 실시간 분석)

  • Yin, Chang-Shik;Choi, Seok-Keun;Lee, Gi-Ja;Eo, Yun-Hye;Kim, Bum-Shik;Oh, Berm-Seok;Lim, Ji-Eun;Lee, Hye-Jung;Park, Hun-Kuk
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.22 no.4
    • /
    • pp.835-840
    • /
    • 2008
  • Acupuncture has long been contended to be effective in an ischemic stroke. A real-time monitoring of glutamate, an excitotoxin in the process of ischemic neuronal damage, in the striatum is tried in a rat model of global ischemia. Global ischemia was induced by the 11 vessel occlusion method for 10 minutes, during which acupuncture stimulation on GB34 and GB39 points was executed. Glutamate release in the rat striatum was monitored 256 times per second using real-time amperometric biosensor. Real time measurement data of 10 minutes prior to the induction of ischemia served as baseline data. Data acquisition continued for 30 minutes after the initiation of reperfusion. Peak concentration of glutamate release along with incidentally measured EEG and cerebral blood flow was compared between cases with and without acupuncture stimulation. Peak concentration of glutamate lowered when acupuncture stimulation was executed. A real time monitoring system of 11 vessel-occlusion induced global ischemia model was successfully established. The effect by acupuncture on acute global ischemia was successfully observed in this real-time monitoring setting, which may be one of the neuroprotective mechanism of acupuncture.

A Study on Biomaterial Detection Using Single-Walled Carbon Nanotube Based on Interdigital Capacitors (인터디지털 커패시트 기반의 단일벽 탄소 나노 튜브를 이용한 바이오 물질 검출에 관한 연구)

  • Lee, Hee-Jo;Lee, Hyun-Seok;Yoo, Kyung-Hwa;Yook, Jong-Gwan
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.19 no.8
    • /
    • pp.891-898
    • /
    • 2008
  • In this paper, we have studied on the possibilities of the biomaterial detection using single-walled carbon nanotube (SWNT) based on interdigital capacitors. For the four different configurations, such as interdigital capacitor, SWNT in the $5\;{\mu}m$ gap interdigital capacitor, biotinlated SWNT, and biotin and sreptavidin immobilization cases, the resonant frequency has been measured as 10.02 GHz, 11.02 GHz, 10.82 GHz, and 10.22 GHz, respectively. Assuming that the resonant frequency reflects the capacitance changes due to binding of two-different permittivity biomaterials, we have suggested an equivalent circuit model based on measured results, confirming the capacitance changes. For biotinlated SWNT and biotin-streptavidin immobilization cases, the capacitances are $C_b=0.55\;pF$ and $C_s=0.95\;pF$. In this work, we experimentally demonstrated that the specific biomaterial binding causes the capacitance change and therefore this gives rise to resonant frequency. In conclusion, we confirmed the sufficient possibility as CNT biosensor because an analyte biomaterial(streptavidin) binding arouses a considerable resonant frequency change.

Heavy Metal Detection and Removal in Artificial Wastewater Using Two-Component System Based Recombinant Bacteria (Two-component System 기반 재조합균을 이용한 인공폐수에서의 중금속 인지 및 제거)

  • Ravikumar, Sambandam;Hong, Soon-Ho;Yoo, Ik-Keun
    • Korean Journal of Microbiology
    • /
    • v.48 no.3
    • /
    • pp.187-191
    • /
    • 2012
  • Two-component system (TCS)-based bacterial zinc and copper biosensors, in which green fluorescent protein (GFP) is expressed under the control of zraP and cusC promoter in ZraS/R and CusS/R TCS, were evaluated in artificial wastewater. Bacterial biosensors developed in this study efficiently expressed GFP by the recognition of $Zn^{2+}$ and $Cu^{2+}$ in artificial wastewater. Secondly, TCS-based zinc and copper removing bacteria with the peptide displayed on cell surface were examined in artificial wastewater. Zinc and copper removing bacteria expressed the peptide as a fusion protein such as OmpC-ZBP (zinc binding peptide) and OmpC-CBP (copper binding peptide) on the cell surface when sensing exogenous $Zn^{2+}$ and $Cu^{2+}$ through ZraS/R and CusS/R TCS. The recombinant cell expressing metal-adsorbing peptide could efficiently remove copper and zinc (15 and 18 mg/g dry cell weight, respectively) in artificial wastewater. Therefore, it was demonstrated that the TCS-based recombinant cell for the recognition or removal of heavy metal functions well in artificial wastewater environment.

Regional Distribution of Isotropy Magnetic Property of Dual-type Giant Magnetoresistance-Spin Valve Multilayer (이중구조 거대자기저항-스핀밸브 박막의 자기등방성 영역분포에 관한 연구)

  • Khajidmaa, Purevdorj;Lee, Sang-Suk
    • Journal of the Korean Magnetics Society
    • /
    • v.23 no.6
    • /
    • pp.193-199
    • /
    • 2013
  • The regional distribution of magnetic isotropy depending on the post annealing condition for the dual-type structure GMR-SV (giant magnetoresistance-spin valve) of NiFe/Cu/NiFe/IrMn/NiFe/Cu/NiFe multilayer was investigated. The rotation of in-plane ferromagnetic layer induced by controlment of the post annealing temperature inside of the vacuum chamber. The magnetoresistive curves of a dual-type IrMn based GMR-SV depending on the direction of the magnetization easy axis of the free layer and the pinned layer are measured by between $0^{\circ}$ and $360^{\circ}$ angles for the applied fields. The optimum annealing temperature having a steady and isotropy magnetic sensitivity of 1.52 %/Oe was $107^{\circ}C$ in the rotational section of $0{\sim}90^{\circ}$. By investigating the switching process of magnetization for an arbitrary measuring direction, the in-plane orthogonal magnetization for the dual-type GMR-SV multilayer can be used by a high sensitive biosensor for detection of magnetized micro-beads.

Electrocatalytic activity of the bimetallic Pt-Ru catalysts doped TiO2-hollow sphere nanocomposites (Pt-Ru@TiO2-H 나노구조체촉매의 합성 및 전기화학적 특성평가)

  • Lee, In-Ho;Kwen, Hai-Doo;Choi, Seong-Ho
    • Analytical Science and Technology
    • /
    • v.26 no.1
    • /
    • pp.42-50
    • /
    • 2013
  • This paper describes the electrocatalytic activity for the oxidation of small biomolecules on the surface of Pt-Ru nanoparticles supported by $TiO_2$-hollow sphere prepared for use in sensor applications or fuel cells. The $TiO_2$-hollow sphere supports were first prepared by sol-gel reaction of titanium tetraisopropoxide with poly(styrene-co-vinylphenylboronic acid), PSB used as a template. Pt-Ru nanoparticles were then deposited by chemical reduction of the $Pt^{4+}$ and $Ru^{3+}$ ions onto $TiO_2$-hollow sphere ($Pt-Ru@TiO_2-H$). The prepared $Pt-Ru@TiO_2-H$ nanocomposites were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), and elemental analysis. The electrocatalytic efficiency of Pt-Ru nanoparticles was evaluated via ethanol, methanol, dopamine, ascorbic acid, formalin, and glucose oxidation. The cyclic voltammograms (CV) obtained during the oxidation studies revealed that the $Pt-Ru@TiO_2-H$ nanocomposites showed high electrocatalytic activity for the oxidation of biomolecules. As a result, the prepared Pt-Ru catalysts doped onto $TiO_2$-H sphere nanocomposites supports can be used for non-enzymatic biosensor or fuel cell anode electrode.

Distribution of Magnetic Field Depending on the Current in the μ-turn Coil to Capture Red Blood Cells (적혈구 포획용 미크론 크기 코일에 흐르는 전류의 크기에 따른 자기장 분포 특성)

  • Lee, Won-Hyung;Chung, Hyun-Jun;Kim, Nu-Ri;Park, Ji-Soo;Lee, Sang-Suk;Rhee, Jang-Roh
    • Journal of the Korean Magnetics Society
    • /
    • v.25 no.5
    • /
    • pp.162-168
    • /
    • 2015
  • The ${\mu}$-turn coil having a width of ${\mu}m$ on the GMR-SV (giant magnetoresistance-spin valve) device based on the antiferromagnetic IrMn layer was fabricated by using the optical lithography process. In the case of GMR-SV film and GMR-SV device, the magnetoresistance ratios and the magnetic sensitivities are 4.4%, 2.0%/Oe and 1.6 %, 0.1%/Oe, respectively. In the y-z plane the distribution of magnetic field of GMR-SV device and $10{\mu}$-turns coil which put under the several magnetic bead(MB)s with a diameter of $1{\mu}m$ attached to RBC (red blood cell) was analyzed by the computer simulation using the finite element method. When the AC currents of 20 kHz from 0.1 mA to 10.0 mA flow to the 10 turns ${\mu}$-coil, the magnetic field at the position of $z=0{\mu}m$ at the center of coil was calculated from $30.1{\mu}T$ to $3060{\mu}T$ in proportion to the current. The magnetic field at the position of $z=10{\mu}m$ was decreased to one-sixth of that of $z=0{\mu}m$. It was confirmed that the $10{\mu}$-turn coil having enough magnitude of magnetic field for the capture of RBC is possible to use as a biosensor for the detection of magnetic beads attached to RBC.